Prior attempts to apply water to a dried glue surface have included the use of a sponge located within a plastic dish which is shaped complementary to the sponge for storage of water. An alternate use of a sponge for application of water to a dried glue surface includes a sponge tip secured to a bottle or tube containing water for gravity flow of water to the sponge tip when in an inverted condition.
In both of these applicators, the dried glue surface is brought into direct pressure contact with the sponge for transfer of water contained within the sponge to the dried glue surface. Over time, due to the direct pressure contact of the dried glue surface with the sponge, the sponge becomes clogged with glue which is picked up by moving the dried glue surface across the sponge or moving the sponge tip across the surface of the dried glue. The glue cakes onto the sponge surface and ultimately forms an impermeable layer. The sponge applicator must then be discarded.
An alternate type of applicator is a porcelain roller moistener. A glazed porcelain roller is rotatably mounted within a water reservoir so that upon rolling of a dried glue surface across the porcelain roller, water is picked up from the reservoir and moves with the roller so as to apply water to the dried glue surface.
Approximately half the diameter of the porcelain roller projects above the uppermost surface of the reservoir. The water level in the reservoir must therefore be kept high by frequent fillings to obtain transfer of water from the reservoir to the roller. However, during rotation of the roller, a non-uniform amount of water is picked up by the roller leaving may open areas of exposure of the roller. The contact of the dried glue layer with the exposed porcelain roller causes transfer of the glue to the surface of the roller.
Again, as in the sponge applicator, a portion of the dried glue surface during each application, is imparted to the porcelain roller. Over time, the dried glue surface builds up and affects the efficiency of the porcelain roller.